System and Method for Cleaning a Gas Turbine Engine and Related Wash Stand

ABSTRACT

A system for cleaning a gas turbine engine may generally include a wash stand having a base frame and a plurality of fluid injection nozzles configured to be supported by the base frame relative to the gas turbine engine. The nozzles may be configured to inject a cleaning fluid through an inlet of the fan casing of the engine as the fan blades are being rotated in a rotational direction such that the cleaning fluid is directed past the rotating fan blades and into a compressor inlet of the engine. Additionally, each nozzle may be oriented at a positive tangential angle defined relative to the rotational direction of the plurality of fan blades. The system may also include a fluid source in flow communication with the wash stand for supplying the cleaning fluid to the plurality of fluid injection nozzles.

FIELD OF THE INVENTION

The present subject matter relates generally to gas turbine engines and,more particularly, to a system and method for cleaning a gas turbineengine and a related wash stand to be used when cleaning the engine.

BACKGROUND OF THE INVENTION

A gas turbine engine typically includes a turbomachinery core having ahigh pressure compressor, combustor, and high pressure turbine in serialflow relationship. The core is operable in a known manner to generate aprimary gas flow. The high pressure compressor includes annular arrays(“rows”) of stationary vanes that direct air entering the engine intodownstream, rotating blades of the compressor. Collectively one row ofcompressor vanes and one row of compressor blades make up a “stage” ofthe compressor. Similarly, the high pressure turbine includes annularrows of stationary nozzle vanes that direct the gases exiting thecombustor into downstream, rotating blades of the turbine. Collectivelyone row of nozzle vanes and one row of turbine blades make up a “stage”of the turbine. Typically, both the compressor and turbine include aplurality of successive stages.

With operation of a gas turbine engine, dust, debris and other materialscan build-up onto the internal components of the engine over time, whichcan result in a reduction in the operating efficiency of suchcomponents. For example, dust layers and other materials often becomebaked onto the airfoils of the high pressure compressor. To remove suchmaterial deposits, current cleaning methods utilize a single guided hoseto inject water into the compressor inlet. Unfortunately, suchconventional cleaning methods often provide insufficient cleansing ofthe compressor airfoils, particularly the airfoils located within theaft stages of the compressor.

Accordingly, an improved system and method for cleaning the interior ofa gas turbine engine would be welcomed within the technology.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

In one aspect, the present subject matter is directed to a system forcleaning a gas turbine engine, wherein the gas turbine engine includes aplurality of fan blades and a fan casing surrounding the fan blades. Thesystem may generally include a wash stand having a base frame and aplurality of fluid injection nozzles configured to be supported by thebase frame relative to the gas turbine engine. The nozzles may beconfigured to inject a cleaning fluid through an inlet of the fan casingas the fan blades are being rotated in a rotational direction such thatthe cleaning fluid is directed past the rotating fan blades and into acompressor inlet of the gas turbine engine. Additionally, each nozzlemay be oriented at a positive tangential angle defined relative to therotational direction of the plurality of fan blades. The system may alsoinclude a fluid source in flow communication with the wash stand forsupplying the cleaning fluid to the plurality of fluid injectionnozzles.

In another aspect, the present subject matter is directed to a methodfor cleaning a gas turbine engine, wherein the gas turbine engineincludes a plurality of fan blades and a fan casing surrounding the fanblades. The method may generally include positioning a wash standrelative to the gas turbine engine. The wash stand may include aplurality of fluid injection nozzles configured to be verticallysupported at a location adjacent to the gas turbine engine. The methodmay also include operating the gas turbine engine such that the fanblades are rotated in a rotational direction about a centerline of thegas turbine engine and injecting a cleaning fluid from the nozzlesthrough an inlet of the fan casing as the fan blades are being rotatedsuch that the cleaning fluid is directed past the rotating fan bladesand into a compressor inlet of the gas turbine engine. Additionally,each nozzle may be oriented at a positive tangential angle definedrelative to the rotational direction of the plurality of fan blades.

These and other features, aspects and advantages of the presentinvention will be better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 illustrates a cross-sectional view of one embodiment of a gasturbine engine that may be utilized within an aircraft in accordancewith aspects of the present subject matter;

FIG. 2 illustrates a simplified view of one embodiment of a system forcleaning a gas turbine engine in accordance with aspects of the presentsubject matter, particularly illustrating the system including a washstand fluidly coupled to a fluid source for supplying a cleaning fluidto a plurality of fluid injection nozzles of the wash stand;

FIG. 3 illustrates a cross-sectional side view of portions of the gasturbine engine shown in FIG. 1 and the wash stand shown in FIG. 2,particularly illustrating the wash stand positioned adjacent to theaxially forward end of the gas turbine engine to allow cleaning fluid tobe expelled from the nozzles and into the interior of the engine;

FIG. 4 illustrates a simplified, radial view of a nozzle of thedisclosed wash stand and a plurality of fan blades of the gas turbineengine, particularly illustrating the differing tangential orientationsof the nozzle and the fan blades relative to the engine centerline; and

FIG. 5 illustrates a flow diagram of one embodiment of a method forcleaning a gas turbine engine in accordance with aspects of the presentsubject matter.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

In general, the present subject matter is directed to a system andmethod for cleaning a gas turbine engine designed for use within anaircraft. In several embodiments, the disclosed system may include awash stand having a plurality of fluid injection nozzles configured toinject a high volume of cleaning fluid through the engine fan and intothe booster compressor for subsequent delivery to the high pressurecompressor of the gas turbine engine. Specifically, the wash stand maybe initially positioned adjacent to the front or forward end of theengine, such as by rolling or moving the wash stand to the location ofthe aircraft or by moving the aircraft to the location of the washstand. Thereafter, with the engine running, a significant volume ofcleaning fluid (e.g., water or any other water-based liquid) may beinjected through the fan in a manner that allows the cleaning fluid tobe directed into the compressor inlet. The high-volume flow of cleaningfluid may then be directed through the booster compressor and/or thehigh pressure compressor as the engine is being operated to allow thecleaning fluid to clean the various internal components disposed alongthe engine's working fluid flow path.

In several embodiments, the orientation of the various nozzles of thewash stand relative to the gas turbine engine may be selected so as toallow the cleaning fluid to be injected past the engine's rotating fanblades and into the compressor inlet. Specifically, as will be describedbelow, the nozzles may be angled relative to the engine centerline suchthat the cleaning fluid is expelled from the nozzles along a flow paththat extends radially inwardly from the nozzle outlets. In addition, thenozzles may have a circumferential or tangential orientation relative tothe engine centerline such that each nozzle is configured to expel fluidat a positive tangential angle (as defined based on the rotationaldirection of the fan blades). As such, as the fan blades rotate withoperation of the gas turbine engine, the cleaning fluid expelled fromthe nozzles may be directed along a positive tangential trajectory thatallows the cleaning fluid to flow between the rotating fan blades andinto the compressor inlet.

It should be appreciated that the disclosed system and related methodmay provide numerous advantages for cleaning the interior of a gasturbine engine. For example, given the ability to provide a high-volume,targeted flow of cleaning fluid into the engine core, a greatercleansing effect may be provided for the interior components of the gasturbine engine, such as the airfoils of the high pressure compressor. Inaddition, given that the cleaning operation is performed while theengine is running, the cleaning fluid directed into the compressor inletwill be heated and pressurized, thereby increasing the likelihood thatany material build-up on the interior components of the gas turbine(particularly the aft airfoils of the high pressure compressor) isremoved and washed out of the system.

Referring now to the drawings, FIG. 1 illustrates a cross-sectional viewof one embodiment of a gas turbine engine 10 that may be utilized withinan aircraft in accordance with aspects of the present subject matter,with the engine 10 being shown having a longitudinal or axial centerlineaxis 12 extending therethrough for reference purposes. In general, theengine 10 may include a core gas turbine engine (indicated generally byreference character 14) and a fan section 16 positioned upstreamthereof. The core engine 14 may generally include a substantiallytubular outer casing 18 that defines an annular compressor inlet 20. Inaddition, the outer casing 18 may further enclose and support a boostercompressor 22 for increasing the pressure of the air that enters thecore engine 14 via the compressor inlet 20 to a first pressure level. Ahigh pressure, multi-stage, axial-flow compressor 24 may then receivethe pressurized air from the booster compressor 22 and further increasethe pressure of such air. The pressurized air exiting the high-pressurecompressor 24 may then flow to a combustor 26 within which fuel isinjected into the flow of pressurized air, with the resulting mixturebeing combusted within the combustor 26. The high energy combustionproducts are directed from the combustor 26 along the hot gas path ofthe engine 10 to a first (high pressure) turbine 28 for driving the highpressure compressor 24 via a first (high pressure) drive shaft 30 andthen to a second (low pressure) turbine 32 for driving the boostercompressor 22 and fan section 16 via a second (low pressure) drive shaft34 that is generally coaxial with first drive shaft 30. After drivingeach of turbines 28 and 32, the combustion products may be expelled fromthe core engine 14 via an exhaust nozzle 36 to provide propulsive jetthrust.

Additionally, as shown in FIG. 1, the fan section 16 of the engine 10may generally include a rotatable, axial-flow fan rotor assembly 38 thatis configured to be surrounded by an annular fan casing 40. It should beappreciated by those of ordinary skill in the art that the fan casing 40may be configured to be supported relative to the core engine 14 by aplurality of substantially radially-extending, circumferentially-spacedoutlet guide vanes 42. As such, the fan casing 40 may enclose the fanrotor assembly 38 and its corresponding fan rotor blades 44. Moreover, adownstream section 46 of the fan casing 40 may extend over an outerportion of the core engine 14 so as to define a secondary, or by-pass,airflow conduit 48 that provides additional propulsive jet thrust.

It should be appreciated that, in several embodiments, the second (lowpressure) drive shaft 34 may be directly coupled to the fan rotorassembly 38 to provide a direct-drive configuration. Alternatively, thesecond drive shaft 34 may be coupled to the fan rotor assembly 38 via aspeed reduction device 37 (e.g., a reduction gear or gearbox) to providean indirect-drive or geared drive configuration. Such a speed reductiondevice(s) may also be provided between any other suitable shafts and/orspools within the engine 10 as desired or required.

During operation of the engine 10, it should be appreciated that aninitial air flow (indicated by arrow 50) may enter the engine 10 throughan associated inlet 52 of the fan casing 40. The air flow 50 then passesthrough the fan blades 44 and splits into a first compressed air flow(indicated by arrow 54) that moves through conduit 48 and a secondcompressed air flow (indicated by arrow 56) which enters the boostercompressor 22 via the compressor inlet 20. The pressure of the secondcompressed air flow 56 is then increased and enters the high pressurecompressor 24 (as indicated by arrow 58). After mixing with fuel andbeing combusted within the combustor 26, the combustion products 60 exitthe combustor 26 and flow through the first turbine 28. Thereafter, thecombustion products 60 flow through the second turbine 32 and exit theexhaust nozzle 36 to provide thrust for the engine 10.

Referring now to FIGS. 2-4, one embodiment of a system 100 for cleaninga gas turbine engine 10 is illustrated in accordance with aspects of thepresent subject matter. Specifically, FIG. 2 illustrates a simplifiedview of a wash stand 102 and various other components of the disclosedsystem 100. FIG. 3 illustrates a side, cross-sectional view of portionsof the gas turbine engine 10 shown in FIG. 1 and the wash stand 102shown in FIG. 2, particularly illustrating the wash stand 102 positionedadjacent to the front or forward end of the gas turbine engine 10 toallow a cleaning fluid to be injected therein. Additionally, FIG. 4illustrates a simplified, radial view of a nozzle 110 of the disclosedsystem 100 as well as a plurality of the fan blades 44 of the gasturbine engine 10, particularly illustrating the differing tangentialorientations of the fan blades 44 and the nozzle 110 relative to theengine centerline 12.

As particularly shown in FIG. 2, the system 100 may include a wash stand102 configured to be in fluidly coupled to a fluid surface 104 (e.g.,via a suitable hose or fluid conduit 106). In general, the wash stand102 may include a base frame 108 and a plurality of fluid injectionnozzles 110 supported by the base frame 108. The base frame 108 may beformed from a plurality of structural members 112, 114 configured tovertically support the nozzles 110 relative to the ground 116. Forexample, as shown in FIG. 2, the base frame 108 may include one or moreframe members 112 configured to be coupled to the nozzles 110 (e.g., viaa nozzle manifold 118) and one or more stand members 114 supported onthe ground 116, with the stand member(s) 114 being configured to becoupled to the frame member(s) 112 so as to maintain the base frame 108vertically upright relative to the ground 116. In the illustratedembodiment, the stand members 114 are shown as being positioned directlyonto the ground 116. However, in other embodiments, a plurality ofcasters or wheels may be positioned between the stand members 114 andthe ground 116 to allow the wash stand 102 to be rolled across theground 116.

It should be appreciated that the specific configuration of the baseframe 108 may be selected such that a vertical height 120 of the washstand 102 corresponds to a suitable height for aligning the nozzles 110relative to the gas turbine engine 10. For instance, as shown in FIG. 3,the dimensions/configuration of the structural member(s) 112, 114 of thebase frame 108 may be selected such that the base frame 108 isconfigured to support the nozzles 110 at a vertical location relative tothe ground 116 that allows the nozzles 110 to be positioned adjacent tothe inlet 52 of the fan casing 40 when the base frame 108 is placed onthe ground 108 proximal to the front or forward end of the engine 10. Inthis regard, it should also be appreciated that thedimensions/configuration of the structural member(s) 12, 114 may beadjustable, as desired or as necessary, to accommodate engines locatedat differing vertical heights relative to the ground 116. For instance,as indicated by arrow 122 in FIG. 2, a length of one or more of theframe member(s) 112 may be varied (e.g., using a telescopingconfiguration) to allow the vertical height 120 of the wash stand 102 tobe adjusted.

In several embodiments, the fluid injection nozzles 110 may be coupledto the base frame 108 so as to form an annular array of nozzles forinjecting a cleaning fluid through the inlet 52 of the fan casing 44 andinto the interior of the gas turbine engine 10. In such embodiments, thewash stand 102 may be configured to be positioned relative to the gasturbine engine 10 such that that a centerline 124 (FIG. 3) of theannular array of nozzles 110 is generally aligned with the centerline 12of the engine 10. As such, each nozzle 110 may generally be positionedat the same radial location relative to the engine centerline 12.

As shown in FIG. 2, in one embodiment, each nozzle 110 may be coupled tothe base frame 108 via a ring-shaped nozzle manifold 118, with thevarious nozzles 110 being spaced apart circumferentially from oneanother around the manifold 118. In such an embodiment, each nozzle 110may be provided in flow communication with a fluid flow path definedwithin the interior of the manifold 118 such that all of the nozzles 110are supplied with cleaning fluid via a common fluid line. For example,as shown in FIG. 2, a fluid conduit 106 may be provided between thefluid source 104 and the manifold 118. As such, cleaning fluid suppliedfrom the fluid source 105 may be directed through the fluid conduit 106and into the manifold 118 for subsequent delivery to each of the nozzles110.

It should be appreciated that, in one embodiment, the manifold 118 maybe configured to be separately coupled to the base frame 108, such as bywelding the manifold 118 to one or more of the frame members 112 or bycoupling the manifold 118 to the base frame 108 via suitable mechanicalfasteners. Alternatively, the manifold 118 may be formed integrally withor otherwise form part of the base frame 108.

It should also be appreciated that the fluid source 104 may generallycorrespond to any suitable fluid source capable of supplying a cleaningfluid to the wash stand 102. In several embodiments, the fluid source104 may be configured to pressurize the cleaning fluid for subsequentdelivery to the nozzles 110. For instance, as shown in FIG. 2, the fluidsource 104 may correspond to a mobile cleaning unit that includes a pump126 configured to receive cleaning fluid from a tank or reservoir 128located within the unit (or from a source external to the cleaning unit)and pressurize the fluid to a suitable fluid pressure. Specifically, inone embodiment, the cleaning fluid may be supplied to the nozzles 110 ata pressure ranging from about 60 pounds per square inch (psi) to about900 psi, such as from about 100 psi to about 700 psi or from about 200psi to about 400 psi and any other suitable subranges therebetween. Aswill be described below, such fluid pressure may be varied, as necessaryor desired, to ensure that the cleaning fluid expelled from the nozzles110 is directed past the fan blades 44 and into the compressor inlet 20.Moreover, the fluid pressure, in combination with the number and orificesize of the nozzles 110, may determine the amount of cleaning fluidinjected into the engine 10. In general, it may be desirable to maximizethe flow amount without inducing any operability issues, such asflameout or stall, for embodiments in which the engine is running duringperformance of the cleaning operation.

Additionally, it should be appreciated that the cleaning fluid usedwithin the system 100 may generally correspond to any suitable fluid.For instance, the cleaning fluid may correspond to a liquid, gas and/orany combination thereof (e.g., foam). In a particular embodiment, thecleaning fluid may correspond to water (e.g., distilled water) or anyother water-based liquid (e.g., a solution/mixture containing water anda cleaning agent or any other suitable additive).

Referring particularly to FIGS. 3 and 4, in several embodiments, thefluid injection nozzles 110 may be configured to be oriented relative tothe centerline 12 of the engine 10 such that the cleaning fluid expelledfrom each nozzle 110 is directed through the fan casing 40 and into thecompressor inlet 20. For example, each nozzle 110 may be orientedradially inwardly relative to the engine centerline 12 such that thecleaning fluid expelled from the nozzles 110 is directly along a flowpath (indicated by arrows 130 in FIG. 3) having a radially inwardcomponent. Specifically, as shown in FIG. 3, each nozzle 110 may extendboth axially aft and radially inwardly at a radial angle 132 definedrelative to the engine centerline 12. In such an embodiment, the radialangle 132 of each nozzle 110 may be selected based on the relativeradial locations of the nozzles 110 and the compressor inlet 120 toprovide the desired flow path 130 for directing the cleaning fluidthrough the fan casing 40 and into the compressor inlet 20.

It should be appreciated that, in several embodiments, the radialorientation of the nozzles 110 may be adjustable to accommodatediffering engine configurations. For example, for an engine having asmaller or larger fan rotor radius, the radial angle 132 of each nozzle110 may be adjusted to account for the difference in the relative radiallocation between the nozzles 110 and the compressor inlet 20 for thesmaller/larger engine. Such adjustability of the radial orientation ofthe nozzles 110 may be achieved using any suitable means and/ormethodology. For instance, in one embodiment, the nozzles 110 may bemovably coupled to the manifold 118 (e.g., via a pivotal or hingedcoupling) to allow the orientation of each nozzle 110 relative to themanifold 118 be adjusted. Alternatively, the nozzles 110 may beremovably coupled to the manifold 118. In such instance, when nozzles110 having a differing radial orientation are desired to be installed onthe wash stand '01, the existing nozzles 110 may be removed and replacedwith nozzles 110 having the desired radial orientation.

Additionally, as shown in FIG. 4, the nozzles 110 may be orientedcircumferentially or tangentially relative to the engine centerline 12to allow the cleaning fluid to be injected past the fan blades 44 andinto the compressor inlet 20 as the fan blades 44 are being rotatedduring operation of the engine 10. Specifically, in several embodiments,each nozzle 110 may be configured to expel cleaning fluid at atangential angle 134 that is oriented in the opposite direction as thecorresponding pre-defined stagger angle 136 of the fan blades 44. Forexample, as shown in FIG. 4, each nozzle 110 may be oriented at apositive tangential angle 134 relative to the engine centerline 12whereas each fan blade 44 may define a stagger angle 136 relative to theengine centerline 12 corresponding to a negative tangential angle. Asused herein, the terms “positive tangential angle” and “negativetangential angle” are used to differentiate tangential angles definedrelative to the rotational direction of the fan blades 44 (indicated bythe arrows 138 in FIG. 4). For example, as shown in FIG. 4, thetangential angle 134 of the nozzle 110 is defined as positive since thetangential component of the angle 134 (indicated by arrow 140) isdirected in the same direction as the rotational direction 138 of thefan blades 44. In contrast, the stagger angle 136 of each fan blade 44is defined as a negative tangential angle since the tangential componentof the angle 136 (indicated by arrows 142) is directed in the oppositedirection of the rotational direction 138 of the fan blades 44.

It should be appreciated that the stagger angle 136 generallycorresponds to the angle defined between a reference line extendingparallel to the engine centerline 12 and a straight line connecting theleading and trailing edges of the fan blade 44. For example, as shown inFIG. 4, each fan blade 44 may include a pressure side 144 and a suctionside 146 extending between a leading edge 148 and a trailing edge 150.As shown in the illustrated embodiment, the leading edge 148 of each fanblade 44 “leads” or is ahead of the trailing edge 150 in the rotationaldirection 138 of the fan blades 44, thereby defining the negativestagger angle 136.

It should be appreciated that the stagger angle 136 of the fan blades 44may generally vary as each fan blade 44 extends radially outwardlytowards the fan casing 40. However, in a particular embodiment, thestagger angle 136 of each fan blade 44 at the radial location at whichthe cleaning fluid is being injected past the fan blades 44 (e.g.,radial locations 152 shown in FIG. 3) may generally range from less thanzero degrees to about −60 degrees, such as from about −10 degrees toabout −50 degrees or from about −20 degrees to about −40 degrees and anyother subranges therebetween.

Additionally, it should be appreciated that the tangential angle 134associated with each nozzle 110 as well as the pressure of the cleaningfluid supplied to the nozzles 110 may generally be selected so as toensure that the cleaning fluid is expelled from the nozzles 110 at asuitable fluid velocity and tangential orientation for allowing all or asignificant portion of the fluid to be directed between the rotating fanblades 44 and into the compressor inlet 20. In this regard, thetangential angle 134 and fluid pressure required to achieve such aresult may vary depending on the engine configuration, namely thestagger angle 134 of the fan blades 44 and the fan rotor radius, as wellas the rotor speed at which the fan blades 44 are being rotated duringthe performance of the cleaning operation. Thus, in several embodiments,the tangential orientation of the nozzles 110 and/or the pressure of thecleaning fluid supplied to the nozzles 110 may be adjusted to providethe desired flow characteristics for the cleaning fluid being expelledfrom the nozzles 110. For instance, in one embodiment, the tangentialorientation of the nozzles 110 may be fixed relative to the manifold118. In such an embodiment, the pressure of the fluid supplied to thenozzles 110 may be adjusted, as necessary, such that the fluid velocityof the cleaning fluid expelled from the nozzles 110 is sufficient toallow the cleaning fluid to be injected past the rotating fan blades 44and into the compressor inlet 20. Alternatively, the tangentialorientation of the nozzles 110 may be adjustable relative to themanifold 118, such as by providing a pivotal or hinged connectionbetween the nozzles 110 and the manifold 118. In such instance, thetangential orientation of the nozzles 110 may be adjusted, either aloneor in combination with corresponding pressure adjustments, to ensurethat the cleaning fluid is directed between the fan blades 44 and intothe compressor inlet 20.

As indicated above, the tangential angle defined by the nozzles 110 mayneed to be varied as a function of numerous turbine parameters,including the rotor speed of the engine 10 during the performance of thecleaning operation. However, in general, the tangential angle 134defined by each nozzle 110 may vary from greater than zero degrees toabout 60 degrees when the engine is operating at a minimum rotor speedor higher (e.g., a rotor speed equal to greater than a rotor speedassociated with a dry motoring speed, an idle speed and/or a partialthrottle speed for the associated engine 10), such as a tangential angleranging from about 10 degrees to about 50 degrees or from about 20degrees to about 40 degrees and/or any other subranges therebetween.

Additionally, it should be appreciated that, in several embodiments, thetangential orientation and/or radial orientation of the nozzles 110 maybe adjusted as a function of the rotor speed at which the engine isrunning during performance of the cleaning operation. For instance, thenozzles 110 may be configured to be set at a predetermined tangentialangle 134 and/or a predetermined radial angle 132 based on the rotorspeed at which the engine is being operated. Such an adjustment to theorientation of the nozzles 110 may be made independent of or incombination to any angular adjustments due to the engine radial size.For example, in one embodiment, the nozzles 110 may be configured to beset at a predetermined tangential angle 134 and/or a predeterminedradial angle 132 based on a combination of the rotor speed and the fanradius.

Referring now to FIG. 5, a flow diagram of one embodiment of a method200 for cleaning a gas turbine engine is illustrated in accordance withaspects of the present subject matter. In general, the method 200 willbe discussed herein with reference to the gas turbine engine 10described above with reference to FIG. 1 and the system 100 describedabove with reference to FIGS. 2-4. However, it should be appreciated bythose of ordinary skill in the art that the disclosed method 200 maygenerally be implemented with gas turbine engines having any othersuitable engine configuration and/or with systems having any othersuitable system configuration. In addition, although FIG. 5 depictssteps performed in a particular order for purposes of illustration anddiscussion, the methods discussed herein are not limited to anyparticular order or arrangement. One skilled in the art, using thedisclosures provided herein, will appreciate that various steps of themethods disclosed herein can be omitted, rearranged, combined, and/oradapted in various ways without deviating from the scope of the presentdisclosure.

As shown in FIG. 5, at (202), the method 200 may include positioning awash stand having a plurality of fluid injection nozzles relative to thegas turbine engine. For example, the disclosed wash stand 102 may bepositioned adjacent to the front or forward end of the gas turbineengine 10 such that the nozzles 110 are configured to inject cleaningfluid through the fan casing 40 of the engine 10. As described abovewith reference to FIG. 3, in one embodiment, the wash stand 102 may bepositioned relative to the gas turbine engine 10 such that thecenterline 124 of the annular array of nozzles 110 is generally alignedwith the engine centerline 12. It should be appreciated that the washstand 102 may be positioned relative to the engine 10 by moving the washstand 102 relative to the engine 10 or by moving the engine 10 relativeto the wash stand 102.

Additionally, as (204), the method 200 may include operating the gasturbine engine such that a plurality of fan blades of the engine arerotated in a rotational direction about the engine centerline.Specifically, as indicated above, the engine 10 may be running duringthe performance of the disclosed cleaning methodology, which may allowthe cleaning fluid expelled from the nozzles 110 to be both heated andpressurized as the fluid is directed through the engine core 14. Inseveral embodiments, the gas turbine engine 10 may be operated at anoperational speed at or above a minimum threshold speed for the engine10. For instance, the minimum threshold speed may correspond to a rotorspeed that is equal to or greater than a rotor speed associated with adry motoring speed, an idle speed and/or a partial throttle speed forthe associated engine 10.

Referring still to FIG. 5, at (206), the method 200 may includesupplying a cleaning fluid from a fluid source to the nozzles of thewash stand. Specifically, as indicated above, the wash stand 102 may befluidly coupled to a suitable fluid source 104 (e.g., a mobile cleaningunit). As such, cleaning fluid may be directed from the fluid source 104to the wash stand 102 (e.g., via a suitable fluid conduit 106).Additionally, as described above with reference to FIGS. 2 and 3, thevarious nozzles 110 may, in one embodiment, be fluidly coupled to acommon nozzle manifold 118. In such an embodiment, the cleaning fluidsupplied from the fluid source 104 may be directed into the manifold 118for subsequent delivery to the nozzles 110.

Moreover, at (208), the method 200 may include injecting the cleaningfluid from the nozzles through a fan casing of the engine as the fanblades are being rotated such that the cleaning fluid is directed pastthe fan blades and into a compressor inlet of the engine. Specifically,as indicated above, the radial and/or tangential orientation of thenozzles relative 110 to the engine centerline 12 may be selected suchthat the cleaning fluid expelled from the nozzles 110 is directedbetween the rotating fan blades 44 and into the compressor inlet 20. Forinstance, as described above with reference to FIG. 4, the nozzles 110may be oriented at a positive tangential angle 134 relative to theengine centerline 12 (as opposed to the negative tangential or staggerangle 136 of the fan blades 44) to ensure that the cleaning fluid isdirected at a suitable trajectory to allow the fluid to be injectedunabated through the fan blades 44.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

1. A system for cleaning a gas turbine engine, the gas turbine engineincluding a plurality of fan blades and a fan casing surrounding theplurality of fan blades, the system comprising: a wash stand, the washstand comprising a base frame and a plurality of fluid injection nozzlesconfigured to be supported by the base frame relative to the gas turbineengine, the plurality of fluid injection nozzles configured to inject acleaning fluid through an inlet of the fan casing as the plurality offan blades are being rotated in a rotational direction such that thecleaning fluid is directed past the plurality of rotating fan blades andinto a compressor inlet of the gas turbine engine; and a fluid source inflow communication with the wash stand for supplying the cleaning fluidto the plurality of fluid injection nozzles, wherein each fluidinjection nozzle is oriented at a positive tangential angle definedrelative to the rotational direction of the plurality of fan blades. 2.The system of claim 1, wherein each of the plurality of fan bladesincludes a leading edge and a trailing edge and defines a stagger anglebetween the leading and trailing edges, the stagger angle correspondingto a negative tangential angle defined relative to the rotationaldirection of the plurality of fan blades.
 3. The system of claim 2,wherein the negative tangential angle ranges from less than zero degreesto −60 degrees at a radial location at which the cleaning fluid isdirected past the plurality of rotating fan blades.
 4. The system ofclaim 1, wherein the positive tangential angle ranges from greater thanzero degrees to 60 degrees.
 5. The system of claim 1, wherein each fluidinjection nozzle is oriented radially inwardly relative to a centerlineof the gas turbine.
 6. The system of claim 1, wherein the cleaning fluidis supplied to the plurality of fluid injection nozzles at a pressureranging from 60 psi to 900 psi.
 7. The system of claim 1, wherein atleast one of a tangential orientation or a radial orientation of each ofthe plurality of fluid injection nozzles is adjustable relative to thebase frame.
 8. The system of claim 7, wherein the at least one of thetangential orientation or the radial orientation of each of theplurality of fluid injection nozzles is configured to be adjusted basedon a rotor speed at which the gas turbine engine is turning while thecleaning fluid is being injected through the inlet of the fan casing. 9.The system of claim 1, wherein the plurality of fluid injection nozzlesare coupled to the base frame so as to form an annular array of nozzles.10. The system of claim 9, wherein the plurality of fluid injectionnozzles are coupled to the base frame via a ring-shaped nozzle manifold.11. The system of claim 1, wherein the plurality of fluid injectionnozzles are configured to inject the cleaning fluid through the inlet ofthe fan casing as the gas turbine engine is being operated at a rotorspeed that is equal to or greater than a rotor speed associated with atleast one of a dry motoring speed, an idle speed or a partial throttlespeed for the gas turbine engine.
 12. A method for cleaning a gasturbine engine, the gas turbine engine including a plurality of fanblades and a fan casing surrounding the plurality of fan blades, themethod comprising: positioning a wash stand relative to the gas turbineengine, the wash stand including a plurality of fluid injection nozzlesconfigured to be vertically supported at a location adjacent to the gasturbine engine; operating the gas turbine engine such that the pluralityof fan blades are rotated in a rotational direction about a centerlineof the gas turbine engine; and injecting a cleaning fluid from theplurality of fluid injection nozzles through an inlet of the fan casingas the plurality of fan blades are being rotated such that the cleaningfluid is directed past the plurality of rotating fan blades and into acompressor inlet of the gas turbine engine, wherein each fluid injectionnozzle is oriented at a positive tangential angle defined relative tothe rotational direction of the plurality of fan blades.
 13. The methodof claim 12, wherein each of the plurality of fan blades includes aleading edge and a trailing edge and defines a stagger angle between theleading and trailing edges, the stagger angle corresponding to anegative tangential angle defined relative to the rotational directionof the plurality of fan blades.
 14. The method of claim 13, wherein thenegative tangential angle ranges from less than zero degrees to −60degrees at a radial location at which the cleaning fluid is directedpast the plurality of rotating fan blades.
 15. The method of claim 12,wherein the positive tangential angle ranges from greater than zerodegrees to 60 degrees.
 16. The method of claim 12, wherein each fluidinjection nozzle is oriented radially inwardly relative to thecenterline of the gas turbine engine.
 17. The method of claim 12,further comprising supplying the cleaning fluid to the plurality offluid injection nozzle from a fluid source, wherein the cleaning fluidis supplied to the plurality of fluid injection nozzles at a pressureranging from 60 psi to 900 psi.
 18. The method of claim 12, wherein atleast one of a tangential orientation or a radial orientation of each ofthe plurality of fluid injection nozzles is adjustable relative to thecenterline of the gas turbine engine.
 19. The method of claim 12,wherein the wash stand further includes a base frame, the plurality offluid injection nozzles being coupled to the base frame so as to form anannular array of nozzles, wherein positioning the wash stand relative tothe gas turbine engine comprises positioning the wash stand relative tothe gas turbine engine such that a centerline of the annular array ofnozzles is aligned with the centerline of the gas turbine engine. 20.The method of claim 12, wherein operating the gas turbine enginecomprises operating the gas turbine engine at a rotor speed that isequal to or greater than a rotor speed associated with at least one of adry motoring speed, an idle speed or a partial throttle speed for thegas turbine engine.